| rpart.poisson {mvpart} | R Documentation |
Set up for poisson method for an rpart model.
rpart.poisson(y, offset, parms, wt)
y |
the responses, a vector or a two-column matrix. If a matrix the first column is the observation times and the second is the counts. |
offset |
an offset, or NULL. The offset is interpreted as
a log observation time. |
parms |
a list of parameters. |
wt |
case weights. |
rpart.poisson is to be used only by the function rpart.
Returns a list consisting of
y |
a matrix giving the observation times and number of events, |
parms |
a named list of parameters, with components shrink
and method (1 for "deviance", 2 for "sqrt"), |
numresp |
the number of responses, here 2, |
numy |
the number of columns in y, here 2, |
summary |
a function to be invoked by summary.rpart, |
text |
a function to be invoked by text.rpart. |